METHOD FOR THE RECOVERY OF INTERNAL COMBUSTION ENGINE PISTONS

摘要

The method is used in repair works of aluminium or cast-ironpistons for ship engines having worn out or damaged piston ringgrooves. It has improved technology and guarantees high wearresistance of the operating surfaces of the piston grooves aftertheir repair. By the method the damaged belts (1) and grooves (2)are cleaned until a common groove (6) is formed which is thenwelded over by low alloyed steel wire under a flux layer. Thewelded piston is placed in a furnace and is annealed after whichits grooves are machined on a lathe and are polished until theirfinal dimensions are reached. The thus treated pistion issubjected to low temperature chemical-and-thermal treatment afterwhich nitrogen and carbon saturation is effected and a diffusionfilm having a depth of 0.3-0.4 mm is formed as well as surfacehardness of the restored surfaces from 650 to 700 HV 10 which isgradually being reduced in depth.